Encryption Works
Micah Lee at The Freedom of the Press Foundation - Government doesn't work, but encryption does. This article contains good directions for using open source encryption software to make your communications much harder for the tyrants to intercept.
The NSA is the biggest, best funded spy agency the world has ever seen. They spend billions upon billions of dollars each year doing everything they can to vacuum up the digital communications of most humans on this planet that have access to the Internet and and the phone network. And as the recent reports in the Guardian and Washington Post show, even domestic American communications are not safe from their net.
Defending yourself against the NSA, or any other government intelligence agency, is not simple, and it's not something that can be solved just by downloading an app. But thanks to the dedicated work of civilian cryptographers and the free and open source software community, it's still possible to have privacy on the Internet, and the software to do it is freely available to everyone. This is especially important for journalists communicating with sources online.